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Development and Validation of Ore Characterisation Test and its Use in Variability Campaigns of Comminution Circuits Impact testing was developed by assessing the fragmentation characteristics of ore samples after controlled impact. Standard methods are, however, limited to relatively large and coarse samples, which thus precludes their use in early stages of projects, as well as where only drill cores are available. The method described in this paper is based on the same concepts of controlled ore breakage, but using relatively smaller samples. It is particularly useful in assessing the variability of ore characteristics in early stages of greenfield projects, as well as in predicting the performance of existing grinding circuits. A validation program was carried out in which a good adherence to the original test results was obtained. The results were used for (a) simulation of a copper comminution circuit as a function of the ore characteristics, and (b) evaluation of sampling protocols used for assessing fragmentation characteristics.

Sep 13, 2010

At the end of August, U.S. producer posting of 99.5 percent unalloyed aluminum had been established at 48¢ per pound. At that time, dealer-quoted unalloyed ingot was reportedly at 44¢-47¢. CADMIUM: By late August, most U.S. producers had raised cadmium selling prices by 25¢ to $3 per pound. As a consequence, dealer quoting of cadmium ranged from $2.95 to $3.05 per pound. COAL: The wildcat strike, which began in southern West Virginia on July 19 and eventually spread to nine other States before ending on August 13, at its peak, idled approximately 115,000 miners and accounted for daily coal losses of an estimated 1.5 million tons at the height of the work stoppage. Concerned about the effects of the production cutbacks, the Bureau of Mines, early in the strike period, initiated its coal strike monitoring system which it had developed during the prolonged coal strike in the fall of 1974.

Jan 1, 1976

By E. O. T. Simpson

"IntroductionAS COMPARED with coal mines in the United States, and even with some of those in eastern Canada, the coal mines of western Canada, generally speaking, :have made little progress toward mechanization at the working faces. So far as Vancouver island is concerned, there are three main reasons for this : ( 1 ) in some areas, conditions• easy for hand-loading but unsuitable for mechanical loading make high outputs per man •possible by the former method; (2) faulting of the coal seams in ..some areas precludes long-term planning and the introduction and efficient use of expensive equipment; (3) thinness •and other characteristics of the seams in many areas favour hand-loading.No. 8 MINENo. 8 mine of Canadian Collieries (Dunsmuir), Limited, is located in the Cumberland sub-area of the Comox coalfield on Vancouver island about 90 miles west-northwest of Vancouver. The geological structure of this coalfield has been described by J. D. McKenzie. The seams occur in the Comox formation, a subdivision of the Upper Cretaceous Nanaimo Group. The formation is of near-shore origin and was laid down on an irregular surface of' older rocks. The irregular generally have a northeasterly dip, modified by gentile folds and by a •few large, and a number of smaller, faults.Four seams have been worked in the Cumberland area and all vary in thickness and in the amount and number of interstratified bone and rock •bands."

Jan 1, 1953

By Paul J. Guay

This report presents the results of evaluating a longwall mining system specifically designed to extract a very deep web (60 inches or deeper) from a longwall panel. The report includes a productivity and cost analysis comparing the new mining sys-tem with a high capacity conventional longwall operation taking a 30-inch wide web. The analysis shows the new system will increase annual production 44 percent and decrease cost per ton off the face 21 percent. The report also includes conceptual drawings and specifications for a high capacity four-drum shearer and a unique shield type of roof support specifically designed for very wide web operation. The advantages and problems associated with wide web mining are discussed in general and as they relate specifically to the equipment selected for the new mining system. The study concludes by recommending that surface coal loading tests be conducted as the follow-on work.

Jan 1, 1978

By G. B. McClurg

China was nota factor in the supply of fluorspar to the United States until the early 1980's when it shipped in its first package of Metallurgical lump, that not only was higher grade than the Mexican Metallurgical spar but was also about $30.00 a ton cheaper landed at Burnside. Representatives of the Mexican Fluorspar Institute and several producers made trips to see the Chinese operations supplying their once reserved market place. China, an enigma to most Westerners suddenly became the new contender, with prices that were disgustingly low or so thought the other exporters. Of course China has been mining, producing, consuming and exporting from 400,000 to 500,000 tons per year of various grades of fluorspar but until the first partloads came to the U.S., very little attention was paid to their exports by American-continent producers or consumers.

Jan 1, 1986

By William Escudero Simon

La Sociedad Minera El Brocal S.A. a través del planeamiento estratégico de la producción (PEP) señala el diseño, desarrollo e implementación de un sistema de costos basados en actividades (ABC, Activity Based Costing). Para implementar el modelo de costos basado en actividades ABC, se redefinió los recursos, procesos, actividades y objetos de costos de la organización. En ese sentido, el presente texto busca diseñar e implementar un sistema de costos ABC que permita ayudar en la toma de decisiones, el mejoramiento continuo de los procesos, obtener ventajas competitivas y una mayor presencia en el sector minero.

Jul 31, 2003

By M. Z. A. Bakar

To investigate the differences in the radial drag pick cutting performance in dry and saturated sandstone, a suite of linear rock cutting test was performed using linear rock cutting machine (LRCM). Experimental results of 50 data passes, incorporating 350 data cuts were used to compute cutting, normal and side forces required for determination of other performance related parameters. Although the forces required to cut the dry and saturated rock were in congruence for most of the spacing and depths of cut combinations; but the overall averaged cutting and normal forces for saturated rock cutting were found to be 9.9% and 9.4% respectively higher than the dry rock cutting. The increase in the overall averaged forces was attributed to strength variability of one of the saturated block affecting the overall forces. The side forces experienced a negligible drop in saturated rock cutting. An increase of 28% and 9% in the actual and nominal specific energy values respectively was also recorded when cutting saturated rock as compared to the dry rock cutting. The increase in saturated rock specific energy is attributed to production of large amount of fines and few large sized chips directly contributing towards increase in specific energy. The optimum s/d ratio for dry rock tests was found to lie between 6 and 8 whereas for saturated rock cuts this value lied between 5 and 9.

Jan 1, 2012

By Glenn L. Allen

The rapid rise of industrial Los Angeles to international prominence has been accompanied by the natural corollary - a record influx of population - together with greatly increased production and fabrication of steel and nonferrous and light metals; industrial mineral processing; and high consumption of fuel oil, gasoline, and chemicals. These have resulted in the release of hundreds of tons of metallurgical and mineral dusts, fumes, and gases into the atmosphere daily. Los Angeles County, intrinsically, is no worse than other industrial centers in respect to the generation of atmospheric contamination. It is, in fact, more fortunate in that no coal is used, and it has no great primary metallurgical industries comparable to those of Chicago and Pittsburgh. Meteorologic and topographic peculiarities of the area, however, which result in poor drainage of the polluted air away from the Los Angeles Basin, serve periodically to greatly increase the intensity and frequency of industrial smog visitations. This combination of intense industrialization, population influx, climate, and topography has made mandatory control of air pollution necessary. The nonferrous pyrometallurgical industry of Los Angeles has three rather unusual characteristics that contribute to its difficulties in developing suitable fume control: It consists of a multiplicity of relatively small establishments subject to wide Variations in products and operating schedules; operations are largely of the secondary or reclaiming nature and, therefore, often work dirty scrap metals; and, unfortunately, much of the industry is concentrated, to a considerable extent, near the center of the city. A difficulty inherent in most nonferrous foundries, including the many brass-works melting alloys containing zinc, is the high volatility of zinc and the extremely small mean particle size of the resulting zinc oxide fume.

Jan 1, 1952

By D. J. Reddish

An understanding of the mechanisms that cause large seismic events in a deep mine provides a foundation for designing effective measures to reduce the incidence of these events, as well as reduce the potential for damage arising from these events. The work described in this paper focuses analytical efforts on major recognizable and controllable factors that influence mining-induced seismicity and serves to screen out many of the more random aspects of individual events. Information used in this study was developed in the course of a long-standing rock burst research program conducted by the U. S. Bureau of Mines in cooperation with mines in the Coeur d'Alene Mining District and regional universities. Information was collected on 39 seismic events having local magnitudes greater than 2.5 that occurred between 1989 and 1994. Five major types of events were developed from these data that describe all but two of the 39 large events. The characteristic mechanisms, tint-motion pattern, damage pattern, and relationships to mining and major geologic structures were defined for each type of event. This information provides a foundation for assessing whether or not changes in mining activity aimed at reducing one type of rock burst will increase the incidence of other types.

Jan 1, 1996

By R. W. Waytulonis

This paper is an update of the activities of the U.S. Bureau of Mines, other government agencies, and the automotive and truck industry concerning diesel emission control. Enacted and proposed regulations from the U.S. Mine Safety and Health Administration (MSHA) and developments in diesel emission control are presented in terms of their impact on underground coal, metal, and nonmetal mines. Mine air quality regulations proposed by MSHA may require the underground mining industry to comply with new standards. Some mines may be required to take additional actions to meet new diesel particulate and lower nitrogen dioxide exposure standards; however, the mining industry is in a position to benefit from emission controls developed for the on-highway diesel engine market. The U.S. Environmental Protection Agency (EPA) has enacted regulations to reduce emissions from on-highway diesel trucks and buses. Engine manufacturers have responded by developing cleaner burning engines. Fuel producers have responded by providing cleaner burning reformulated diesel fuel, and exhaust aftertreatment devices have been developed to provide additional emissions reductions. Bureau research and development projects seek to determine the advantages of using modern engines and fuels, and to evaluate the efficacy of new exhaust control devices on mining machines. It appears that the diesel engine will continue to be a practical power source for use in confined environments because no other available power source is as mobile and efficient.

Jan 1, 1993

By André de Almeida Grilo

Correias transportadoras de alta temperatura são ativos críticos para a pelotização devido ao prejuízo que sua falha pode trazer para a produção. Nesse sentido, deve-se avaliar a vida útil da correia em uso, visando, principalmente, auxiliar sua manutenção, e nesse contexto o presente trabalho tem como proposta utilizar a caracterização dos componentes e o estudo da degradação térmica do material da cobertura de correias transportadoras de alta temperatura. As caracterizações foram realizadas de modo comparativo entre três tipos distintos de correias transportadoras de alta temperatura fornecidas para a VALE S.A. Os reforços das correias foram caracterizados por FT-IR para análise qualitativa do polímero. De maneira semelhante, as borrachas foram caracterizadas por meio da análise do produto de pirólise via FT-IR e a densidade de ligações cruzadas por meio da técnica de inchamento do polímero e aplicação da equação de Flory-Rhener, o que ajudou a justificar o comportamento das diferentes marcas de correia perante a degradação térmica, estudada em um trabalho anterior. A partir desses resultados e utilizando dados de variação das propriedades mecânicas do material em função do tempo e temperatura de processo, pôde-se avaliar a taxa de dano causado a cada correia e, aplicando-se dados reais de processo, avaliou-se o desempenho das correias em trabalho.

Aug 8, 2018

By A. Ochieng

Solids suspension influences the quality of mixing and energy requirement in a solid-liquid system, both of which determine the efficiency of industrial processes such as nickel precipitation. Nickel solids concentration distribution in a stirred tank was investigated using computational fluid dynamics (CFD) and experimental methods. The concentration distribution of the nickel solids was compared with that of sand and glass. The laser Doppler velocimetry (LDV) method was used to measure the velocity field for the liquid-only system and an optical technique was employed to determine the axial solids concentration distribution. Regions of in homogeneity in the tank were identified. It was found that, for a given solids loading, the solids concentration distribution depended on both particle size and particle size distribution. High solids loadings were investigated and a difference in the concentration distribution pattern was obtained with nickel, flint glass and sand particles. The CFD simulation results highlighted problems that could be associated with some conventional experimental methods of determining solids concentration distribution in a stirred tank. Keywords: nickel; CFD; simulation; mixing; solids suspension.

Jan 1, 2010

By Efstratios Karampinos, John Hadjigeorgiou, Philippe Morissette

"Ground support is a critical element in maintaining the stability of mining drives in deep and high stress mines. In challenging ground conditions, it is necessary to continuously explore ground support strategies that can control the resulting large deformations. It is an objective of mining operations to optimize the ground support by selecting appropriate systems at the time of installation of each reinforcement element. A successful ground support strategy will result in the use of a system that ensures both the structural and operational integrity of the excavations and mitigates the need for rehabilitation.Preliminary ground support design is often based on empirical observations and methods. Once a design is implemented, field trials, observations and in situ pull tests are used to fine tune or improve the design. Although not often employed during this process, numerical modelling can provide helpful insights into the impact of different ground support strategies. In this respect, it is possible to explore the use of multiple options before selecting the most promising ground support system for implementation in field trials. The challenges associated with the numerical modelling of rock support for mines have been described by Lorig and Varona (2013) and Potvin (2017). The employed numerical models should capture all potential failure modes of reinforcement throughout the mining sequence of the excavation. In particular, it is important to emulate the observed in situ ground support performance, as well as the influence of the installation sequence of the support. However, the time and expertise required for this type of modelling of ground support is often not available at mine sites. Even when the expertise is available, it requires a major time commitment and commitment of resources to set up, run and calibrate the sophisticated models capable of explicitly capturing the behavior of ground support.Rock reinforcement is an integral part of all ground support systems used in underground mines. Long, flexible tendons can reinforce the rock mass deeper into the walls and create a thicker reinforced shell around the underground excavation. This article focuses on the optimization of the cable-bolting strategy in squeezing conditions at the LaRonde Mine in Quebec, Canada by integrating the 3D distinct element method (DEM) in the design process. A calibrated numerical model is used to investigate a series of cable bolt configurations and provide recommendations for the ground support design."

Jan 4, 2018

By C. S. Chenga

Sustainable development is currently an extremely relevant concept worldwide, especially in developing countries like South Africa. Mining and metals companies are also directly affected by the sustainable development agenda. The Mining Charter?s requirements as well as new legislation (Mineral and Petroleum Resources Development Act) expect, among others, for mines to support infrastructure and poverty eradication projects in the communities surrounding the mines. The aim of this paper is to, against the background of a qualitative study of mining communities in the North-West Province of South Africa, put forward some critical factors for the sustainability of social development projects in the mining sector.

Jan 1, 2006

By S. N. Monteiro, N. A. Cerqueira, E. B. Zanelato, J. Alexandre, M. T. Marvila, B. C. Mendes, A. R. G. Azevedo, G. C. Xavier

Mortar is a widely used building material and has its application in buildings in extremely vulnerable environments and susceptible to degradation, such as facades. The objective of this work was to evaluate the loss of mechanical resistance to compression and flexure and the loss of mass of the mortars with effluent sludge from paper industry, when exposed to saline environments. The specimens were done with 0, 5, 10 and 15% of incorporation in lime paste and subjected to saline mist equipment that sprays salt solution in cycles simulating natural degradation conditions using literature data. It can be concluded that mortars with a15%incorporation obtained a significant loss of mass and a decrease in their mechanical resistance, which impairs their use in civil construction and influence in other properties of the material, with a level of incorporation of 10% the results within Brazilian standards.

Mar 1, 2018

By D. H. Ryan, B. Abdul, M. Pernechele, E. Asselin

Hydrometallurgical processing of sulphide concentrates at medium temperature (150°C) produces residues, which contain valuable metals (Cu, Ni) as well as sulphur and iron bearing minerals and phases. The low solubility of iron during the medium temperature processing of sulphide ores can favour the formation of poorly crystalline, nano-scale iron oxide/oxyhydroxide phases. A better understanding of the formation and structure of these iron precipitates may elucidate key factors that would ultimately result in lower valuable metal losses and more stable leach residues. Residues from two medium temperature leach processes were characterized by Mössbauer Spectroscopy. Some portions of the Mössbauer Spectrum were suspected to be linked to jarosite but could not be positively identified as such. There was a broad range of disorder and substitution present in the material and solely attributing it to jarosite proved difficult. Various synthetic jarosites with Cu substitution were precipitated for Mössbauer analysis. These were then characterized by Quantitative X-Ray Diffraction (QXRD), Scanning Electron Microscopy (SEM), Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) and Mössbauer Spectroscopy. The Mössbauer Spectra of the synthetic jarosites is compared with that of the residues from medium temperature (150°C) sulphide concentrate leaching.

Jan 1, 2014

By Joël P. T. Kapusta

Back in 1995, Air Liquide and Union Minière presented a joint paper at the Copper 95 – Cobre 95 Conference in Santiago, Chile, describing the first full scale plant trials of shrouded sonic injection in a Hoboken converter at the Hoboken smelter in Belgium. Almost a quarter of a century later, the technology known as ALSI, or Air Liquide Shrouded Injection, has been tested or commercially implemented in several copper and nickel smelters. Despite these successes, the copper industry did not adopt it widely in the same manner the steel industry adopted the Savard-Lee tuyere in the 1970s and beyond, not even in the way the lead industry adopted it with the Queneau-Schuhmann-Lurgi, or QSL, process. The development and implementation of bottom-blowing smelting and converting technologies in China in the last ten years, however, changed the industry’s perception that high- and ultra-high oxygen injection in copper smelting and converting was indeed possible under specific process conditions. In this paper, I retrace the key learnings of my journey with sonic injection over the twenty five years from my humble beginnings in my early years with Air Liquide, through plant trials and technology implementation in the late 1990s and into the first decade of the new millennium, and ultimately, to the most conclusive proof that the sonic injection design methodology I established is valid, and the calculation tools I developed are accurate. I conclude by sharing my thoughts about whether the deployment of the Savard and Lee legacy within the nonferrous industry was just a pipe dream or whether it will become a reality. INTRODUCTION In the context of lower quality ores and changing economic markets, copper smelters need to continuously innovate and improve to remain competitive and respect their corporate social responsibility engagements. One avenue towards this business, social, and environmental goal is to increase process intensity while lowering fossil fuel consumption to lower greenhouse gas emissions and reducing process off-gas volumes to better capture As and SO2–laden emissions. I believe high oxygen sonic injection for submerged tuyere copper bath smelting and converting is one technology that can help smelters achieve that goal of higher business, social, and environmental performance. Twenty five years ago, when I discovered that the Savard-Lee tuyere had revolutionized the steel industry (Savard & Lee, 1966; Knuppel, Brotzmann, Fassbieder, Savard, & Lee, 1972), I had a dream — or was it a vision? — that within the first decade of the new millennium, modern copper smelters operating submerged tuyere bath smelting and converting vessels will have implemented high oxygen sonic injection and will be reaping the financial and environmental benefits that the steel industry enjoyed in the 1970s. As we approach the end of the second decade of the new millennium, I have to admit that my dream has been all but shattered as the majority of copper bath smelting and converting vessels today continue to operate under bubbling regime conditions. This mode of operation is archaic, still requires tuyere punching and blows at inherently low enrichment levels, particularly in converting, producing large volumes of process off-gases. Under such operating conditions, regulations and emission quotas for As, SO2, and particulate matter oblige smelters to use not just primary or secondary hoods, but sometimes even tertiary hoods. I vividly recall being told, fifteen or twenty years ago when visiting smelters to promote the application of the Savard-Lee tuyere in nonferrous processes, that implementing sonic injection was not economically viable due to the high cost of compressing air and oxygen. Some of the smelters I visited back then have since mandated their engineering partners to design and build secondary or even tertiary hoods. I cannot fathom how secondary and particularly tertiary hoods, with all of their auxiliary equipment and added ducting, could be more economically viable than purchasing and installing a few compressors, expanding the pipeline network for compressed air and oxygen, and installing a new control valve train to feed sonic tuyeres. Besides, adding hoods does not address the problem of As and SO2-laden fugitive emissions at its source but merely provides a costly mitigation for it by capturing larger volumes of process off-gases rather than reducing these large volumes in the first place. Moreover, hooding does not reduce energy consumption nor does it increase process intensity, two aspects that I believe are critical for smelters to remain competitive and sustainable in a deeply changing market environment.

Jan 1, 2019

By N. V. Nayak

Maharashtra State Road Development Corporation Ltd., has initiated a scheme for construction of 55 flyovers in Mumbai in India. To ensure speedier completion of projects several new technologies were adopted to save time without compromising on safety and reliability. Many of the flyovers involved large diameter pile foundations carrying loads ranging from 3500kN to 1375kN. Significant time would have been lost in using conventional load testing procedure to check pile capacity apart from the difficulty in mobilizing the load and the obstruction to site movement and traffic on the adjoining roads. High Strain Dynamic Testing was introduced on the project sites in lieu of static load testing after conducting numerous co-relation studies on various project sites. A total of seven co-relation studies have been conducted till date and based on these data static testing has been replaced by dynamic testing on numerous flyovers. The paper presents the results of such studies. CAPWAP analysis was also conducted on the data to evaluate the percent skin friction and end bearing so as to improve future design parameters.

Jan 1, 2000

By Peter B. Knuckey

1, Introduction Location Kalengwa mine is located in the North Western Province of Zambia, 402 kilometre by unpaved road to the west of Kitwe, which is roughly in the centre of the Zambian Copperbelt, well known as one of the world's centres of copper mining. Its position is illustrated on the map of Africa in Figure 1 and on the map of Zambia in Figure 2. It is a mine of Roan Consolidated Mines Limited whose other properties, Mufulira, Luanshya, Chambishi and Chibuluma Mines, are all located on the Copperbelt. It is managed by the Chibuluma Division of the company. The rate of production from Kalengwa will vary from 12 000 to 17 000 tonnes of saleable copper a year over the next six years. Kalengwa did not exist as a place until the first prospecting parties and later the mine became established and the early working population was recruited entirely from small villages in the surrounding area as much as thirty miles away. The mining area consists of fourteen mining locations amounting to 3.35 square kilometres and the land may be used for any purpose connected with mining, including housing, wood cutting and other utilities. The whole area is, except for minor undulations, a fairly flat plateau with main rivers running from north to south and flood basins known as "dambos" located in a general east west direction. Vegetation is, with the exception of the grassy dambos, temperate forest with relatively light undergrowth. Game of great variety is prolific, as is the associated tsetse fly.

Jan 1, 1971

By William Gleason

From Nov. 16-20, the Extraction 2025 Conference will be presented in Phoenix, AZ. The unique conference brings together the 12th International Copper Conference, the 6th International Symposium on Nickel and Cobalt as well as cross-cutting symposia. Extraction 2025 is co-organized by The Metallurgy and Materials Society (MetSoc) of the Canadian Institute of Mining, Metallurgy and Petroleum (CIM), the Society for Mining, Metallurgy & Exploration (SME) and The Minerals, Metals & Materials Society (TMS). The previous, and first Extraction meeting (Extraction 2018) was held jointly by these three societies seven years ago in Ottawa and was a huge success with more than 90 percent of respondents indicating interest in attending a future event. Kimberly Mills, senior process engineer at Samuel Engineering, is the lead for SME. “This installment of Extraction is featuring Copper 2025, Nickel-Cobalt 2025 as well as crosscutting symposia,” said Mills. “All three societies participate on the International Organizing Committee for the Copper Conference Series and are well situated to host this event together. TMS is also hosting the Ni-Co conference this year and agreed to include it as part of Extraction. There are many aspects that can be shared between these commodities to share information on processing technologies and to learn from each other.” SME is the overall conference chair and running the logistical aspects of the event, which includes managing all aspects of the venue and the registration system as well as tours and short courses, Mills said. “SME has many dedicated members serving in various capacities on organizing and programming committees, including Nick Gow serving as Technical Committee Co-Chair for Copper and Adam House assisting on the Copper IOC.” When Extraction 2025 kicks off, it will be focused on the metals needed for the global energy transition with a special focus on copper and nickel-cobalt. “With as rapidly as the industry is changing and the huge demands for these metals we have some serious challenges ahead of us,” Mills explained. “These challenges require collaboration, creative solutions and engaging experts, both inside and outside of our fields, with a push for sustainable sourcing, ethical supply chains, environmental and social responsibility.” The International Copper Conference was started in 1987 as a collaboration between the Institute of Mining Engineers of Chile (IIMCH) and MetSoc of the CIM. The event is typically held every four years and has always been held as a standalone or headlining event at a society annual meeting, said Mills. “Over the years, this conference series alone has brought together members of IIMCH, MetSoc, TMS, SME, the Society for Metallurgists and Miners from Germany (GDMB), the Mining and Materials Processing Institute of Japan (MMIJ), the South African Institute of Mining and Metallurgy (SAIMM) and the Nonferrous Metals Society of China (NFSOC),” she added. “Being a part of Extraction allows for even more sharing of ideas and expansion of networking. This conference has not been held in the United

Oct 1, 2025